I forgot the mechanism so
@jimmysmith560 or some cracked ATAR theorist/analyst who spent their past life devoted to ATAR theory lol can explain it in detail but I saw it in effect for my internal vs external mark being top 1 in all my HSC subjects.
Basically, if you're #1, you get the highest HSC exam mark as your internal mark so suppose your friend joshua got 95 on the HSC exam and you got 80, you'd basically get 80 on your external mark and 95 as your internal mark with scaling or smthn.. I got the highest exam marks for all my subjects so basically my internal and external were the same mark and so my final mark for the subject was just my exam mark.
The aggregate of your marks gives you some mark out of 500 and that determines your ATAR.
HORRIBLE EXPLANATION, MIGHT BE BANNED, COULD BE INACCURATE BUT THATS THE JIST FROM WHAT I SAW FROM MY HSC.
So for me this kinda explained why the main advice for students in low ranked schools was to get #1 in your subjects so in that way your internal mark would be the highest possible and you had full control over your external. Since you're #2, you'll experience something similar to this where you might be Joshua who gets top exam mark 95 on your external but your internal might be lower 93 persay since your #1 student in your subject takes that 95 for their internal with their own external mark. (Assuming all the processes are done).
Why did I write all this? Basically just another way of saying, go do good in your external by studying and stop worrying about ATAR predictions lol, if you pull a 99 on all your exams you can still get a high ATAR but if you're the type of guy to get 70-80 maybe you might be sitting mid 80s etc.. No one really knows how good you really are at the HSC (bc u might be doing school tasks harder than the HSC paper or papers way easier, most likely not due to ur ranking and if so you might be getting 75-80s as everyone's saying, IDK UR ABILITY ).